Removed extra ')'.

docs/userguide/canvas.rst

@@ -250,7 +250,7 @@ The Primitives
         Chunking splits a long list of arguments into parts, e.g the operation::
 
             >>> items = zip(xrange(1000), xrange(1000))  # 1000 items
-            >>> add.chunks(items, 10))
+            >>> add.chunks(items, 10)
 
         will split the list of items into chunks of 10, resulting in 100
         tasks (each processing 10 items in sequence).